Ore reduction mill



y 1941- G; F. AINSA 2,248,921 ORE nnnucmon MILL I Filed April 11. 19:58 2 Sheets-Shet i INVENTOR, Geo as For: A/NsA Jig-fig. v. v BYI/ July 15, 1941.

G. AINSA ORE REDUCTION MILL 2 sneex's-snet- 2 mad April 11. 1958"- E-Ib' a reducing mill-having the above characteris- '20 arrows, and .tics, wherein the unreduced agglomerate will Figures is a similar view taken along line berecirculated through the mill in' a continuous IVIV of Figure 1, looking in direction of arrows. manner until reduced .to a required fineness. In Figure 1 of the drawings there isillustrated Another object of the present inventionis to in its entirety a mill constructedin accordance provide an agglomerate reducing mill acting 35 with'this invention, which i's'particularly adaptedupon-the emtrifugai principle, whereina circulato the reduction of loose and lumpy material, tion-of-ahismelied uponto separate and -withsuch as metal bearing ores, cement, rock, clay draw theredufied agglomerate from the mill and the. like. As here shown, the various elewhen'ithls-been reduced'tothe proper fineness. ments of the mill are mounted in cooperating Another object of the present invention is to 40 relation upon a suitable structural iron frame "I provide a reducing'mill of a character similarin having a pedestal II at one end, upon which many respects to'that described in my copending there is journaled a centrifugal rotor element I 2, a plication for Letters Patent, Serial No.- 14,012, andat the other end of the frame Hi there is illed April 1.1935. and now Patent No. 2,171,526, a suitable platform arrangement I: to facilitate entitled Reduction mill. 45 the feeding of the material to be reduced to In the-art to which the present invention themilL'as will-hereinafter appear. The centrif- BQ. h 1188 b s l '8 l rge number' ugal agglomerate throwing rotorelement I2 is of mills for reducing agg om u .w 1 carried by a horizontally disposed shaft ll which posin -m sses of asglomerate are held by centrifis journaled in a bearin l5 and driven through veal force and caused to rub againsteach other, 50 a belt l6 by an electric motor IL. B tween reducing mill of the type in which member.

reduced by impaction against said surface.

Patented July 15, 1941 UNITED j STATES;

PATE T oFFica ORE REDUCTION MILL George Foye Ainsa, San Francisco, Calif., assignor of one-third to to Eugene de generally to a an agglomerate of loose lumpy material. is reduced or pulverized by impaction of the larger particles of agglomerate-against a stationary impact receiving surface, and more particularly to a reducing mill, wherein the impact action is produced by a centrifugally operating agglomerate throwing The present invention relates Another object of the present invention is to provide a reducing mill'for the reduction of coarse'and lumpy agglomerate, wherein the unreducedfi s'lomerate is thrown by centrifugal ain'st a-i.-elatively stationary mass of agglomerate to reduce the agglomerate by the impact between the centrlfugally thrown and stationary agglomerate' Another object of the invention is to provide so as to obtaina reducingaction' by" friction against op osing masses of agglomerate. In

reducing mills of this character the agglomerate is reduced slowly by a rubbing action which takes place between the relatively moving particles of 6 Dolores 0. Alma and Reynier," Berkeley, .Calif.

Application April 11, 1938, Serial No. 201,232 f 3 Claims. ,(01. 83-43) at its ends with rails I9 and one-third the agglomerate as-these particles travel under the influence of centrifugal force and pass out of the mill at the periphery of centritugally operating and opposed rotor elements. Such.

between the particles, and consequently a large amount of power is Asdistinguished from .the prior art mills, the present invention contemplates a free throwing of the agglomerate by centrifugal force from a suitable rotor element and against a stationary impact receiving surface, where the agglomerate will be reduced by impaction.

For a better understanding and its mode of operation, "reference should be had to the accompanying :drawings, wherein there is shown of limitation, a preferred embodiment thereof.

In the drawings, wherein like numerals desig-' nate like parts throughout Figure l is a vertical side parts in section, struction thereof,

Figure 2 is a plan view along line II--H of the mill illustrated in Figure 1, also having parts broken away and in section, so as to reveal'details of construction, I Figure 3 is an end view of the mill taken along line'IlIIlI of Figure 1, looking in direction of the several views;

I the pedestal II and the platform ll the frame, Iois adapted to support a rotatable drum-like housing. which is here designated generally by the numeral l8. This housing I8 is" provided that engage and reducing mills require an excessive pressure necessary to operate the mill.-

of the invention 7 by wayof illustration and not view of a mill, with to disclose the interior con- 2 ride upon spaced supporting rollers 2i and 22 in a manner well understood in the art. At the outer end of the rotatable housing. 18 there is an annular driving rack 23, which in cooperation with a spur gear 24 upon the end of the shaft of a motor 25 is adapted to provide a driving means therefor. Arranged adjacent the other side of the rotatable housing l8 there is an arch-like stationary agglomerate intercepting member 26 which is disposed over and around the open end of the centrifugal rotor element l2 and against which the by centrifugal force from element l2 will strike. This stationary agglomerate intercepting member 2%, which is shown in the form of an arch that bridges over the' open end of the rotor element 12 may be of solid construction, but is preferably of open construction, so that it will accumulate and retain a mass of agglomerate 21 in a position where the agglomerate will provide a constantly renewing surface against-which the centrifugally thrown agglomerate will strike. As a resultof this construction it will be seen that both the accumulated agglomerate 21 retained by the member 26 and the thrown agglomerate will be subject to reduction by impaction, and as a result the efii-. ciency of the mill at the same time the necessity for replacing worn parts. such as is required in mills having metallic grinding surfaces, will be reduced to a minimum, and further, a contamination of the reduced agglomerate by metal worn from the mill parts will be eliminated.

As illustrated, the stationary member 26 is of hollow rectangular cross-section and is provided with an open an ular area 28 around its inner wall through which the agglomerate 21 may be initially projected from the centrifugal rotor element l2 to build up an impact receivin surface of the agglomerate 21. It will be understood as the agglomerate thrown from the centrifugal rotor element i2 is acted upon, the unreduced particles will flow down by gravity over an inclined chute 29 properly positioned at the lower part of the stationary member 26, where it will be discharged into the rotatable drumlike housing l8. In order to insure a discharge of the unreduced agglomerate to the rotatable housing l8 the stationary agglomerate intercepting member 26 is provided with an outwardly extending dischargedirecting flange 30. which projects through an opening 3| in the adjacent wall of the rotatable housing, 48. Disposed substantially centrally of the-rotatable housing l8 and opposite the open end of the centrifugal rotor member i2 there is a fixed bafiie 32 upon the inside surface of which there is provided a shock absorbing,- facing 33 of rubber or like material.- This bafiie 32 serves to prevent a direct discharge of any of the unreduced agglomerate from the centrifugal rotor element l2 into the rotatable housing l8, except at a point near the bottom of the rotatable housing I8, where the unreduced particles gravity into the rotatable housing l8. At this point it will be noted that the flange 30 is ina'gglomerate thrown the centrifugal rotor will be greatly increased and will be discharged b! clined downwardly so as to permit thisdischarge of the agglomerate into the rotatable housing I8. Arranged in spaced relation throughout the inner periphery of the rotatable housing I8. there is a plurality of buckets 34 which are inclined so as to pick up and carry the agglomerate discharged therein to a point corresponding to their uppermost point of travel, where the agdischarged through glomerate carried by the individual buckets 34 will be discharged into a stationary hopper 35 which, as shown, has its agglomerate receiving end 36 disposed beneath the buckets 34 within the rotatable housing l8 and its agglomerate discharging end 31 disposed so as to direct the returned agglomerate to a point near the outer periphery of the centrifugal rotor element 12 where, due to the high linear speed of the rotor-element at this point, the agglomerate will be subjected to intense frictional heat, which in the case of sulphite bearing ores will result in a burning of these impurities as well as in a reduction of the ore by impaction as it is thrown against the impact receiving surface of agglomerate 21 formed, as described above, upon the stationary agglomerate intercepting member 26. An additional feature of the stationary hopper 35 is that one of its sides, designated by the numeral 38, is carried upwardly in a direction substantially tangent to the axis of the centrifugal rotor element l2, where it will recapture any agglomerate which the centrifugal rotor and which is not thrown out against the surface of agglomerate 21 by centrifugal force by the rotor element l2. For the purpose of introducing agglomerate into the mill constructed as above described, the. rotatable housing 18 is provided with a centrallydisposed stationary end closure plate 39 which is carried by the frame It), and extendingthrough this end closure plate 39 there is a stationary chute 40 having a hopper-like agglomerate receiving end 4|, and positioned below and partially around the chute 40 the end closure plate 39 has a semiannular manifold 42 from which a suction conduit 43 extends. In operation the suction conduit 43 will be connected to a suitable suction type blower which will create a circulation of air through the mill to carry away all agglomerate which is reduced to a proper fineness. In order to limit the discharge of agglomerate to a particular fineness, the intake opening of the manifold 42 may be provided with a screen 44 of suitable mesh. when suction is produced upon the outlet pipe 43, air will be drawn into the mill, in the main, through an opening 45 which is provided at the rear of the centrifugal rotor member i2. Air will also find admission into the mill in the clearance space 46 between the wall of the rotatable housing 18 and the flange 3i carried by the stationary agglomerate intercepting member 26. The intake of air 'at these points will also serve to prevent the escape of any reduced agglomerate from the mill in the form of dust, and as a result no precaution to avoid such an escape at-these points will be necessary. In order to maintain this suction and prevent any short circuiting of the air flow, as described above. by the inlet of air through the chute 40. this chute is provided withopposed damper-like e ements 41 which are biased into a closed position by weighted ends 48. When agglomerate is to be introduced into the. mill it will first be deposited in the hopper-like end 4| of the chute 40 and then the damper-like elements 41 will be opened to permit a dischargeof the agglomerate into the mill, after which the damper-like elements" will-be permitted to again close.

when the mill, constructed as described above, is in operation, it will be seen that the agglomerate may be deposited in the hopper 4i and the chute 40 by an opening of the damper-like elements 41. This will permit may rebound within fiiatth -thatthe circulation air passing 'andhavinga the agglomerate to fall down into the bottom oi'the rotatable housing l8 where the buckets 34,

burn out any volatile substances carriedby the', ore, as for example, sulphites and the like. As the rotatable element l2 rotates it will also carry the major portion of the thereupon around by centrifugal force and disthe stationary agglomerate the bottom of the stationary member 28 where it will now flow by gravity over the lip 30-and into the lower part or the rotatable housing l8. ,This 5 I upon the inner unreduced agglomerate'will then be again picked; up by the buckets 34 and return to the hopper eupper end of the chute 35 for a repetis tion or the above reduction cycle.

suction blower connected to the outlet conduit 43 is operating, and as a result the rlnely reduced agglomerate will be picked up by the through the openings 46 01' the mill and carried out the outlet conduit 43 for further treatment.

I I have, for the sake of clearness in order to disclose my invention so that the it is desired to claim it so that all such changes Having thus described my invention, what 1 scribed, the combination of a'bowl-lik centrif- Iiaally operating 'agglolnerate receiving memer isposed to rotate about a. horizontal axis tical plane, a stationary aeglomerate intercepting m mber disposed outwardly in spaced relation. and in the plane of the open end of said cen,

ally operating bowl-like member, said star ,be- 70 tionary aealomerate intercepting membe I means, new

in: inthe idrmaoi a hollow arch forming a cavity At this point it -10 I2, excessive Iric- 0 rtional heat W111 be created w ch will serve to the above operation it will be assumed an thmugh that this invention is new and claim and desire to secure bv LettersPatent isco 1. In a reduction mill otfthe character desingle 'open' end disposed in a vertending .into

- box-like portion of said ceivin'g member during the operation of the mill, and a discharge outlet leading from said agglom-' tionary agglomerate intercepting member adapted to receive agglomerate as it falls from said member, an agglomerate directing. chute for directing agglomerate into said centriiugally ope'rmember when z. in a reduction mill of the character: de-

scribed, the combinat on or a bowl-like centrifugally operating agglomerate receiving member disposed to rotate about a horizontal axis" and h'avmga single open end disposed in a vertical plane, a i stationary agglomerate intercepting member disposed outwardly. in spaced relation and in the plane of the ugally operating bowl-like member, said station- 25 ary agglomerate intercepting member being in the io'rm of a hollow arch that bridges over and extends downwardly along each side of said bowlnke m emner and terminates in'a chute-like discharge outlet, a rotatable drum-like housing 0 disposed adjacent said stationary agglomerate insuri'ace 21, the unreduced particles will fall down by gravity into tercepting member adapted to receive'agglomerate as it rails from said member,

received agglomerate back to said chute, whereby and a second agglomerateintroducing chute exsaid rotatable drum-like ho through which the agglomera'te is initially introduced into the mill. 3. In a reduction scribed, the combination or a horizontally disposed bowl-likeelement adapted to be rotated at a highspeed about a horizontal axis with its 'open end disposed in a vertical plane, means for continuously feeding agglomerate into the open end-or said rotatablebowl-like element, whereby said introduced agglomerate will be continuously thrown by centrifugal end or said bowl-like thrown agglomerate intercepting member disposed in a vertical plane and extending over and around the open end of said bowl-like element having an open'boz-like portion adapted to temporarily retain a part of, the agglomerate thrown out by centrifugal force rotatabl element will A ally renewing impact receiving surface or the agglomerate temporarily retained in the open stationary impact reerate intercepting member to said continuously the thrownand temflnt bridges over and e t d d wnwardly 91mg pora'rily-retained agglomerate will be subjected bowl-like, member-and tennieach side or r and discharge outlet, arotatable nates' n ashute-nke to further reducing action.

' aroma more AlNBA.

mrotatlon, and a open end 01 said centritan agglomerate. directing chute. ior directing agglomerate into i said centrizugally operating bowl-like member itv is reduced to a desired fineness,

mill or the character de-* force through the openelement, a stationaryfrom said bowl-like element, whereby the agglomerate thrown from said impact against a continu- I 

